Web or strip material handling apparatus

ABSTRACT

Web material is processed through a magazine mechanism which stores a quantity of such web material, thereby to permit successive rolls of the web material to be spliced together without stopping the processing. The magazine comprises two relatively movable sections which come together gradually as web material is given up from the magazine during the splicing operation; and gradually part, after splicing is effected, thereby to refill the magazine. Means is disclosed for assuring that the movement of the relatively movable magazine parts do not cause undulation or the like within the web material.

United States Patent Bruton 51 June 13, 1972 [54] WEB OR STRIP MATERIALHANDLING APPARATUS [72] Inventor: John M. Bruton, North Harrow,Middlesex, England [73] Assignee: Eastman Kodak Company, Rochester,

[22] Filed: March 12, 1970 21 Appl. No.: 18,896

[30] Foreign Application Priority Data March 21, 1969 Great Britain..l4,938/69 [52] U.S. Cl ..242/75.4, 226/189, 242/55.01, 242/58.1

[51 Int. Cl. ..B65h 23/06, B65h 51/20 [58] Field ofSearch..242/75.4,58.1, 75.44, 55.01, 242/753, 75.51; 226/118, 119, 189

[56] References Cited UNITED STATES PATENTS 1,286,331 12/1918 James..242/75.44

3,258,214 6/1966 Comstock..... 242/753 X 3,278,100 10/ l 966 Hornberger..226/ l 89 3,414,208 12/1968 Butler ...242/58.1 3,249,316 5/1966 Loose"242/75 .44

Primary Examiner-George F. Mautz Assistant Examiner-Edward J. McCarthyAttorney-Walter O. Hodson and Robert F. Cody [57] ABSTRACT Web materialis processed through a magazine mechanism which stores a quantity ofsuch web material, thereby to permit successive rolls of the webmaterial to be spliced together without stopping the processing. Themagazine comprises two relatively movable sections which come togethergradually as web material is given up from the magazine during thesplicing operation; and gradually part, after splicing is effected,thereby to refill the magazine. Means is disclosed for assuring that themovement of the relatively movable magazine parts do not causeundulation or the like within the web material.

PATENTEDJUH 1 3 I972 SHEET 10F 2 JOHN M. BRUTON SHEEI 2 OF 2P'A'TENTEDJunJ 3 I972 a/VETVTOR. 9

JOHN M. BRUTON 1 ATTOR/VE 5 WEB R STRIP MATERIAL HANDLING APPARATUSBACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to web -or strip material handling apparatus and moreparticularly, but not exclusively, to an apparatus for providing anuninterrupted supply of web or strip material at a substantiallyconstant tension, from a discontinuous source.

2. Description Relative to the Prior Art As web and strip materials areusually supplied in roll form, an apparatus for supplying web or stripto a process which relies upon a continuous intake of such material mustbe able to continue supplying the web or strip even during replacementof the supply roll.

An apparatus which has been developed for this purpose comprises astationary group of horizontally disposed rollers arranged in horizontalalignment with their axes parallel and equidistantly spaced, and asimilarly disposed and arranged group of rollers beneath the stationarygroup and free for vertical movement in parallel relation with respectthereto. The lower movable group of rollers is biased for downwardmovement, for instance, by its own weight, and the rollers of this groupare in staggered relationship with the rollers of the upper stationarygroup. Together, the two groups of rollers form part of asupply-magazine.

When web or strip material from a supply-roll thereof is alternatelythreaded around successive rollers of each group so as to follow aserpentine path through the magazine, the length of such path and hencethe capacity of the magazine to store material can vary according to thevertical distance between the two groups of rollers. This tends towardsa maximum due to the bias applied to the lower movable group of rollers.

Upon depletion of the supply-roll further intake of material into themagazine is for the moment stopped while a fresh supply-roll issubstituted and the leading end thereof spliced to the trailing end ofthe deplete roll. During this time, however, material can continue to bedrawn from the store thereof in the magazine by virtue of the lowergroup of rollers being raised, by the material, towards the upperstationary group of rollers. This causes a shortening of the serpentinepath of the web in the magazine. Upon completion of the supply-rollchangeover and resumption of intake of web or strip into the magazine,which, of course, has to be accomplished before depletion of the supplyof material in the magazine, the lower group of rollers, because of itsown weight, moves downwardly away from the upper group of rollers.Hence, the magazine can replenish itself with material in readiness forthe next replacement of the supply roll.

In practice, the supply-roll can be braked in order to produce a tensionin the web or strip material. If, however, the lower group of rollersdescends unevenly during replenishment of the supply-magazine and/orcomes to an abrupt halt at the bottom of its travel, unwantedfluctuations in web or strip material tension can occur which might evencause breakage of the web or strip material.

SUMMARY OF THE INVENTION According to the present invention, there isprovided web or strip material handling apparatus comprising rotatablemeans for supporting a roll of the material, guide means arranged toguide the material to'or from the roll and to provide a guide path forthe material variable in length between a maximum and a minimum formaintaining a correspondingly variable store of the material therein, anelectrical mechanism directly responsive to the rate of variation of thelength of the guide path, and means responsive to electric signals fromthe electrical mechanism for controlling rotation of the rotatablemeans.

An object of the present invention is the provision of an apparatus forproviding a continuous supply of web or strip material at substantiallyeven tension.

By way of example, the invention will now be described with reference tothe accompanying drawings in which:

FIG. 1 illustrates schematically a preferred embodiment of a web orstrip material handling apparatus according to the invention; and

FIG. 2 illustrates an alternative arrangement of the apparatus shown inFIG. 1.

Referring to FIG. 1 of the drawings, and to the position of theapparatus shown therein, a supply-roll l of web material 2 is mounted ona free running shaft 3 to which a braking force can be applied by meansof a magnetic particle clutch 4. The clutch 4 comprises a stator and arotor mounted for rotation with the shaft 3. The web 2 passes from I thesupply-roll 1 thereof over a splicing table (not shown) and past a websensing device (also not shown) and through a rechargeablesupply-magazine denoted generally by the number 5 and thence to asubsequent web-treatment-process (not shown), by the action of a drawingforce F in the direction of the webtreatment process.

The supply magazine comprises a vertical kingpost 6 at the top of whichis supported in fixed horizontal relation thereto a beam 7 carrying anarray of horizontally disposed top rollers 8 arranged in horizontalalignment with their axes parallel and equidistantly spaced. A beam 9carrying a similarly disposed array of bottom rollers 10 is mounted onthe kingpost 6 beneath the beam 7 and in parallel relation with respectthereto, the bottom rollers 10 being in staggered relationship with thetop rollers 8. The beam 9 is free to slide vertically up and down on thekingpost 6 in parallel relation with respect to the beam 7; however, theweight of the beam 9 and the rollers 10 supported thereon tends to keepthe distance between the top rollers 8 and the bottom rollers 10 at amaximum.

With web threaded alternately around successive top and bottom rollersas shown, that is, so as to follow a serpentine path through themagazine, the quantity of web stored in the magazine as determined bythe length of the serpentine path of web in the magazine, will be amaximum due to the gravitational bias of the bottom roller-array as longas web continues to unroll from the supply-roll. A web tension can beobtained by appropriate adjustment of the braking effect exerted by themagnetic clutch on the supply-roll, which, in turn, is governed by theposition of the bottom roller array as will be described hereinafter.Upon depletion of the supply roll, the trailing end thereof moves by theweb sensing device which actuates a clamp 11 to clamp the end before itenters the magazine. Preferably, however, the clamp can be operatedmanually when it is noticed that the supply roll is nearing depletion.The clamp 11, for example, can be a pair of braked rollers. While afresh supply-roll is being substituted for the deplete roll and theleading end thereof is being spliced to the trailing end of the depleteroll, intake of web into the supply-magazine is, for the moment,stopped; however, web can continue to be drawn from the store of web inthe magazine at the rate required for feeding into the subsequentweb-treatment-process by virtue of the web itself raising the lowerroller array and shortening the serpentine path of the web in themagazine. In order to avoid an interruption in web supply, thesupply-roll changeover and the resumption of web intake into themagazine by the releasing of the clamp must, of course, be accomplishedbefore the bottom roller-array has risen to meet the top roller array.Upon the resumption of intake of web into the magazine, the bottomroller-array descends, thereby increasing the length of the serpentinepath which the web has to follow through the magazine, again to build upa store of web therein in readiness for when the next fresh supply-rollis required.

It will be appreciated that if the velocity of the bottom roller-arraythroughout its descent is uneven, unwanted fluctuations in web tensionwill occur. Also, if the bottom rollerarray is brought to an abrupt haltat the bottom of its travel this could result in a momentary acutedecrease in web tension caused by overrun of the supply-roll 1, followedby a severe jerk which might even cause breakage of the web.

In order to prevent such fluctuations in web tension occurring, the rateof descent of the bottom roller-array is automatically controlled bymeans of an electrical mechanism which causes the magnetic clutch 4 toapply a braking force to the shaft 3 on which the supply-roll 1 ismounted, throughout the descent of the bottom roller-array.

Referring again to FIG. 1, the electrical mechanism comprises, on theone part, a tacho-generator 17 which is operatively connected to thebeam 9 through a chain and sprocket assembly 18 and a 25:1 step-upgearbox l9 and, on the other part, a potentiometer 13 which can beactuated also by the beam 9 via a trip-arm 12, a tie-rod l4, and aquadrant and pinion assembly 15 against a light tension spring 15a.Current to the magnetic clutch 4 can be varied by the control-unit 16which receives signals from both the potentiometer 13 and thetacho-generator 17.

The descent of the bottom roller-array causes the tachogenerator 17 toproduce an electric signal. This signal is received by the control-unit16 which in turn causes the electric current to the magnetic clutch tobe varied to increase the coupling between the rotor and stator andthereby the braking effect exerted on the supply-roll-shaft 3 in directrelation to the magnitude of the electric signal. As a result of thisdirect relationship, the velocity of the bottom roller-array during thedescent thereof is accurately controlled. As the descent of the bottomroller-array is nearing completion, the potentiometer 13 is actuated byreason of the beam 9 engaging the trip-arm l2, and a second electricalsignal, of increasing magnitude, is received by the control-unit 16.This in turn causes a further controlled increase in the electriccurrent to the magnetic clutch 4, whereby the braking force exerted onthe supplyroll-shaft 3 is increased. The signal from the potentiometerl3 overrides the reducing signal from the tacho-generator l7 andthebottom roller-array is brought to rest.

Thus, since there is an interrelation between the braking force of themagnetic clutch and the velocity of the bottom roller-array throughoutthe whole of the descent thereof during replenishment of thesupply-magazine, even tension in the web is ensured. There may be slightchanges in web tension as the bottom roller-array starts its descent andas it is completing its descent when the potentiometer is actuated tobring the bottom roller-array to rest but, by appropriate adjustment,these changes in tension can be kept to an ineffective minimum.

The control means of the present invention is readily adapted to controlthe rate of filling and/or emptying of a magazine. It is an advantage ofthe apparatus that the supplyroll braking control is self-compensatingfor changes in diameter of the supply roll and that it is not'necessaryto have a follower arm to sense changes in diameter of the supply roll.

It will be appreciated that the apparatus described above can be appliedto provide a substantially constant tension from a continuous source toan interrupted takeup of web or'strip material on a re-wind roll.Referring to FIG. '2, in such instance, a magazine 20 operates inreverse and a rewind roll 21 would be driven by a prime mover (electricmotor, not shown) via a magnetic particle clutch 22 operating under slipconditions, and a tacho-generator 23 would be used to control the clutch22 during emptying of the magazine 20 after a takeup roll had beenchanged.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

lclaim:

1. Web material handling apparatus comprising rotatable means forsupporting a roll of the material, guide means arranged to guide thematerial with respect to the roll and to provide a serpentine guide pathfor the material variablein length between a maximum and a minimum formaintaining a a correspondingly variable store of the material therein,said guide-means comprising relatively movable arrays of rollers, meansresponsive to the rate of variation of the length of the guide path forproducing a signal representative of said rate, 1

and means responsive to signals from the rate responsive means forcontrolling rotation of the rotatable means, whereby the relativemovement of said arrays 'of rollers is controlled.

2. Apparatus according to claim 1 wherein the rotatable means is freelyrotatable, and wherein the means for controlling rotation of therotatable means is a signal responsive brake.

3. Apparatus according to claim 1 including means responsive to therelative position of the said arrays of rollers for over-riding signalsfrom said rate responsive means.

4. Apparatus according to claim 3, wherein the rate responsive means isa tacho-generato'r, and wherein the tachogenerator is adapted to bedriven by relative movement of the arrays of rollers.

1. Web material handling apparatus comprising rotatable means forsupporting a roll of the material, guide means arranged to guide thematerial with respect to the roll and to provide a serpentine guide pathfor the material variable in length between a maximum and a minimum formaintaining a correspondingly variable store of the material therein,said guide means comprising relatively movable arrays of rollers, meansresponsive to the rate of variation of the length of the guide path forproducing a signal representative of said rate, and means responsive tosignals from the rate responsive means for controlling rotation of therotatable means, whereby the relative movement of said arrays of rollersis controlled.
 2. Apparatus according to claim 1 wherein the rotatablemeans is freely rotatable, and wherein the means for controllingrotation of the rotatable means is a signal responsive brake. 3.Apparatus according to claim 1 including means responsive to therelative position of the said arrays of rollers for over-riding signalsfrom said rate responsive means.
 4. Apparatus according to claim 3,wherein the rate responsive means is a tacho-generator, and wherein thetachogenerator is adapted to be driven by relative movement of thearrays of rollers.